Illuminated push-pull switch operator



Oct. 14, 1969 J. E. STALLMAN ILLUMINATED PUSH-PULL SWITCH OPERATOR FiledFeb. 12, 1968 FIG. I

22 Is 5M2 JAMES E. STALLMAN Flea United States Patent US. Cl. 200--167 9Claims ABSTRACT OF THE DISCLOSURE An illuminated push-pull switchoperator having a tubular operating stem which is resiliently maintainedin selected operating positions in a base by spring biased cam membersthat move in a circumferential path about outer surface portions of thestem.

This invention relates to push-pull type switch operators and moreparticularly, to a switch operator which has a linearly movable tubularstern and a means for resiliently maintaining the stem in at least oneposition against linear movement in a base.

Devices known as heavy duty oil tight push button selector switches andthe like which are furnished by manufacturers for industrial typecontrol frequently are designed to use a minimum number of separatecomponents which may be readily modified and combined to provide amaximum number of selected switching functions. To achieve the desiredflexibility, the oil tight switching apparatus combination usuallyincludes one or more individual contact blocks each of which has alinearly movable plunger and movable contacts within the block toachieve the desired switching function and a manually operated switchoperator to move the switch plunger. Additionally, the combination mayinclude an element known as a light module which is provided if anilluminated switch operator is desired. An example of a contact blockwhich may be used with the operator according to the present inventionis shown in a United States Patent No. 3,336,455, filed May 5, 1965 andissued Aug. 15, 1967 which has been assigned by the inventors Merlin Y.Turnbull, Josef Bierenfeld and Carl B. Sohns to the assignee of thepresent invention. The operator according to the present invention maybe used as a replacement for the switch operator shown in Turnbull etal. patent or the operator shown in United States Patent No. 3,320,393which was filed Nov. 15, 1965 and issued May 16, 1967 and also assignedby the inventors Carl B. Sohns and Josef Bierenfeld to the assignee ofthe present invention. Additionally, if desired, the operator accordingto the present invention may be used with a light module in a mannerdisclosed in United States Patent No. 3,315,- 060, filed Nov. 8, 1965and issued Apr. 18, 1967, which was assigned by the inventors Richard D.Rothweiler, Josef Bierenfeld and Carl B. Sohns to the assignee of thepresent invention, if an illuminated form of the switch operator isdesired.

The present invention relates to devices commonly known as push-pulloperators which may be used instead of two or more switching operators,as are more commonly used in motor control circuits. A typicalinstallation wherein the switch operator according to the presentinvention may be used in a motor control circuit is accomplished byarranging the electrical connections to the switches operated by theswitch operator so the motor will start when the operating button of theoperator is manually pulled outwardly from a central or neutral positionand the motor will stop when the operating button is pushed inwardlypast the neutral position. The operator structure further includesreadily interchangeable parts 3,472,986 Patented Oct. 14, 1969 whichwill cause the operator parts to be resiliently maintained in both thepulled-out and the pushed-in positrons, or will cause the operator partsto be resiliently maintained in the neutral position or combinationsthereof, as desired.

It is an object of the present invention to provide a self-containedswitch operator which may be attached to other switching units toprovide a switching assembly and wherein the operator includes aplurality of members which are movable in a circumferential path about atubular operating stem to resiliently maintain the stem in one or morepositions in a passage through a base of the operator.

Another object is to provide a self-contained push-pull button operatorfor actuating switch contacts in a separate contact block which isattached to the operator to provide a switching assembly and to providethe operator with a tubular stem of translucent material so atranslucent button carried on the stem may be illuminated and toresiliently maintain the stem in one or more selected positions in apassage through a base of the operator with a means that includes atleast one pair of cam members which are carried in an annular groove inthe base.

Further objects and features of the invention will be readily apparentto those skilled in the art from the specification and appended drawingillustrating certain preferred embodiments in which:

FIG. 1 is a cross sectional view of a switch operator incorporating thefeatures of the present invention.

FIG. 2 is a view partly in cross section, generally taken along line 22in FIG. 1.

F16. 3 is a front elevational view of a portion of a tubular stemoperator together with one form of a cam indexing structure used in thestructure shown in FIG. 1.

FIG. 4 is a front elevational view of a portion of a tubular stemtogether with a modified form of the cam indexing mechanism shown inFIG. 3.

Referring to FIG. 1 of the drawings, the switch operator 10 includes ametal base 12 having a forward end 14, a rear end 16 and a passage 18extending therethrough between the forward end 14 and the rear end 16.At its rear end 16 the base 12 is provided with circumferentially spacedbosses 20 which are internally threaded, as indicated at 22, forcooperation with suitable bolts, not shown, and an adapter 26 forsecuring the base 12 to switches 28 in a manner as described in theTurnbull et al. patent.

The forward end 14 of the base 12 has an inwardly extending annularflange 30 restricting the forward end of the passage 18 and providing anupper wall of an annular groove 32 which has a lower wall provided by anannular washer 34. An annular seal 36 having a V- shaped cross sectionis positioned within the groove 32 to engage with a sealing engagementouter wall portions of a tubular stem 38 that extends through thepassage 18. Extending rearwardly of the washer 34 the passage 18includes an enlarged annular portion or annular groove 40, the top wallof which is provided by the washer 34 and the bottom wall of which isprovided by a cam member retainer 42. The retainer 42 is annular inshape and is held fixed within the passage 18 by staking inner Wallportions of the base 12 over a bottom surface of the retainer, asindicated by the numerals 44.

Suitably secured to a forward end of the stem 38 is a head portion, oroperating button 46. As shown, the outer surface of the forward end ofthe stem 38 is provided with an externally threaded portion 48 whichreceives an internally threaded portion on the button 46 thereby unitingthe button 46 and the stem 38 into a single assembly with an annularseal 50 being provided to preclude travel of undesirable fluids from theexterior of the stem 3 38 about the threaded portion 48 into theinterior of the tubular stem 38.

The stem 38 is guided for axial movement in the passage 18 by innerannular wall portions of the flange and the retainer 42 with entry offluids flow about the stem 38 into the passage 18 being prevented by theseal 36. The movement of the button 46 and the stem 38 rearwardly in thepassage 18 is limited by engagement between a rearwardly located annularsurface 52 on the button 46 and the forward end 14 of the base 12.

In order to limit the forward movement of the stem 38 relative to thebase 12, a retainer 54 is connected to the rearward end of the stem 38.The retainer 54 is arranged to engage the bottom surface of the retainer42 to limit the forward movement of the stem 38 in the passage 18.

The retainer 54, as disclosed in the Sohns et al. patent, is annular inshape and has an internal annular head or shoulder extending radiallyinwardly from its inner periphery and terminating axially in spacedrelation to the ,rear end of the retainer 54. The rear end of the stem38 is provided with a radially open annular groove 56 and a taperedguiding nose portion 58. The stem 38 has two axially extending notches60 extending through its peripheral wall. The retainer 54 is providedwith radially extending tongues which are receivable in the notches 60with circumferential clearance. The notches 60 impart a certainflexibility to the extreme rear end of the stem 38. The stem 38 and theretainer 54 are made of relatively stiff, but slightly resilient,self-restoring material. The stem 38 and retainer 54 can be assembled bypressing the retainer 54 forward end foremost over the tapered guidingnose portion 58 of the stem 38, thus contracting the rear end of thestem 38 radially and expanding the retainer 54 until a rib on theretainer 54 passes into alignment, radially of the stem, with the groove56. Thereupon the retainer 54 and the stem 38 approach fully restoredcondition, seating the rib firmly in the groove 56. The tongues on theretainer 54 fit the notches 60 with very limited circumferentialclearance when the stem 38 is contracted. Hence, when the retainer 54 issnapped into place, the notches 60 in the rear end of the stem 38 firmlyengage the tongues on the retainer 54 and assure that when the retainer54 is self-restored to its original condition, it is constrained fromrotation relative to the stem 38.

As shown in FIGS. 2, 3, and 4, integrally formed to extend outwardly onopposite sides of outer surface portions of the stem 38 are cam pins 62and 64. The cam pins 62 and 64 are identical and each includes a pair ofoppositely facing rounded cam surfaces 66 which are spaced on oppositesides of a strengthening rib 68 extending tangentially and axially alongthe outer surface of the stem 38. Each of the pins 62 and 64 is providedwith a raised portion 70 which engages the inner wallsof the passage 18to further guide the movement of the stem 38 in its movement in thepassage 18.

Positioned on opposite sides of each of the cam pins 62 and 64, as shownin FIG. 2, is a pair of cam members. The pair of cam members positionedon the opposite sides of the cam pin 62 are designated by numerals 72and 74. Similarly, cam members 76 and 78 are positioned on oppositesides of the cam pin 64. The cam members 72, 74, 76, and 78 areidentical and each is arcuately shaped to be received in the groove 40and movable in the groove 40 in a circumferential path about an outerperipheral surface of the stem 38. The cam members 72, 74, 76 and 78each has a cam surface on one end and a notch on an end remote from thecam surface. In FIGS. 3 and 4, the notches are designated by the numeral80. The cam surfaces in FIG. 3 on the illustrated cam members 72 and 74are designated as 72a and 74a, while in FIG. 4 the cam surfaces on apair of cam members 73 and 75 are designated as 73a and 75a. It is to beappreciated that an additional pair of cam members, not shown havingsimilar cam surfaces as cam members 73 and 75 are used in the structurein FIG. 4 to provide the functions provided by the cam surfaces 72a and74a in FIG. 3 and the cam surfaces 73a and 75a in FIG. 4, as will belater described. If desired, portions of the cam members 72-76 and 78may be removed as designated by the numeral 82 for mechanical clearancepurposes. As shown in FIGS. 2 and 3, the cam members 72 and 74 arepositioned in the groove 40 on opposite sides of the cam pin 62 so thatthe cam surfaces 72a and 74a confront each other with the cam pin 62being positioned therebetween. The cam members 76 and 78 shown in FIG. 2are similarly disposed in the groove 40 so the cam surfaces there onconfront each other with the pin 64 positioned therebetween.

The cam surfaces 72a and 74a each has a cam profile that is valley orV-shaped, providing a pair of inclined surfaces 84 and 86 extending inopposite directions from an apex 88. Similarly, the cam surfaces 73a and75a each have a cam profile that is wedged or V-shaped, providinginclined surfaces 90 and 92 extending from an apex 94. In theembodiments shown in FIGS. 3 and 4, a pair of springs 96 are positionedwithin the groove 40 and each has opposite ends positioned within thenotches 80 to urge the confronting cam surfaces 72a, 73a, 74a, and 75ainto constant engagement with the cam surfaces 66 of their associatedcam pins 62 and 64.

The assembly of the switch operator may be accomplished as follows. Theoperating button 46, which may be of translucent material and which maybe provided with an ornamental annular bezel 98, is threadedly appliedto the threaded portion 48 after the seal 50 is in position on the stem38. The assembled button 46 and the stem 38 is then installed in thepassage 18 as the tapered nose 58 is passed through central opening inflange 30. The seal 36 is positioned within groove 32 and washer 34 ismoved into the position shown in FIG. 1. An assembly, consisting of thecam members 72, 74, 76 and 78 together with a pair of springs 96, ispositioned within the annular groove 40 and the cam retaining member 42is moved in position and there held by staking a portion of the base 12as indicated by the numeral 44. When the foregoing parts have beenassembled, the retainer 54 is secured to the rear end of the tubularstem 38 in a manner previously described.

The forward end of the base 12 is externally threaded, as indicated at100 for receiving an internally threaded ring nut 102. The base 12 canreadily be inserted through an opening in a panel 104 after the nut 102is removed and oil seal washers 106 are positioned between a rear faceof the panel and an annular external shoulder 108 on the base 12. Afterthe base 12 and the washers 106 are thus positioned, a suitable indiciaplate 110 having an annular opening may be positioned over the forwardend 14 to be positioned between the front face of the panel and the nut102 when the nut 102 is reapplied to the threads 100. If desired, thebase 12 and the indicating plate 110 may be held against rotationrelative to the panel 104 by a conventional projection-notch arrangementas is well known.

When a non-illuminated type of switch operator is required, the adapter26 and one or more switches 28 are secured to the rear end of the switchoperator 10 in a manner previously described and fully disclosed in theSohns et al. patent. Each of the switches 28, as disclosed in the Sohnset al. patent, has a pair of upper statipnary contacts, a pair of lowerstationary contacts, and a movable contact carried by a switch plunger112. The plunger 112 is spring biased outwardly of the housing of theswitch 28. When the plunger 112 is moved inwardly to an intermediateposition within the housing of switch 28, neither of the pairs ofstationary contacts of the switch 28 is bridged by the movable contactso that the switch is in a circuit opening position. The components ofthe switch 28 and the switch operator 10 are arranged so that when thestem 38 is positioned as shown in FIG. 3, the switch plunger 112 willposition the movable contacts of the switch 28 in a circuit openingposition. Thus as the operating button 46 is pulled outwardly of thebase 12, the stem 38 will move upwardly and the cam surfaces 66 willmove upon the inclined surfaces 84 and cause the cam member 72 to moveto the left against the force of one of the springs 96 while the cammember 74 moves to the right against the force of the other spring 96.The upward movement of the stem 38 in FIG. 3, which is limited by theengagement of the retainer 54 with the retainer 42, is accompanied by anupward movement of the plungers 112, which causes the movable contactswithin the switches 28 to complete circuits through the upper pairs ofstationary contacts of the switches 28. When the manual force which isapplied to button 46 is released, the springs 96 will move the cammembers 72 and 74 toward each other with a force which will cause theplunger 38 to move downwardly to the position wherein the rounded camsurfaces 66 are positioned in the apexes 88 to resiliently maintain thestem 38 in a neutral position within the housing 12.

When a manual force is applied to the button 46 to move the buttoninwardly into the base 12 to a position wherein the surface 52 engagesthe flange 30, movement will be imparted to the stem 38 which will causethe cam surface 66 to move on the inclined cam surface 86. The movementof the camming pin 62 will cause the cam members 72 and 74 torespectively move against the force of springs 96. When the button 46 isbottomed on the flange 30, the plungers 112 of the switches will bedepressed through the movement of the retainer 54 to a position whereinthe lower set of stationary contacts of the switches 28 are bridged bythe movable contact. When the force upon the button 46 is removed, thecam members 72 and 74 will automatically cause the stem 38 to moveupwardly to the position wherein the rounded surfaces 66 are positionedin the apexes 88 to again maintain the stem 38 in a neutral position.Thus in the embodiment shown in FIG. 3, a continued manual force must beapplied when the button 46 is either pulled outwardly of the base 12 orpushed inwardly into the base 12 and the camming arrangement, includingthe camming pins 62 and 64, together with the cam members 72, 74, 76 and78, will constantly urge the movement of the stem 38 to a neutralposition wherein the contacts of the switches 28 are in a circuitopening position.

When the cam members shown in F164 are utilized in the switch operator10, the cam members 73 and 75 will maintain the stem 38 in an upperposition in the base 12, as shown in full lines, or in a lower position,as shown by the broken-lined cam member 62a. When the elements of theswitch operator are positioned as shown in full lines in FIG. 4, thebutton 46 and the stem 38 will be in the pulled-out position relative tothe base 12 and the upper set of contacts of the switch 28 will be in acircuit closing position. When it is desired to open the upper set ofcontacts in the switches 28 and close a circuit through the lower set ofcontacts of the switches 28, the button 46 is manually moved inwardly inthe base 12 toward the position wherein the cam pin 62 is positioned asshown in broken lines indicated as 62a. During the foregoing movement,the rounded surfaces 66 will initially pass over the inclined surface 90and move the cam members 73 and 75 apart against the forces of thesprings 96. When the rounded surface 66 passes beyond the apexes 94, themanual force which is applied to button 46 to move the stem 38 inwardlyinto the base 12, may be removed and the stem 38 will continue to moveautomatically to the broken-line cam pin 62a position as the forceexerted by the springs 96 upon the cam members 73 and 75 urges theinclined surfaces 92 against the rounded surfaces 66 so that the stem 38will move to its lower position and close the lower contacts of theswitch 28.

When the elements, including the stem 38 and the cam pin 62a of theswitch operator 10, are positioned as shown in broken lines in FIG. 4,the button 46 and stem 38 will be in the push-in position relative tothe base 12 and the lower set of contacts of the switch 28 will be in acircuit closing position. When it is desired to close the upper set ofcontacts in the switches 28 and open a circuit through the lower set ofcontacts in the switches 28, the button 46 is manually pulled outwardlyfrom the base 12 toward the position wherein the cam pin 62 ispositioned as shown in full lines. During the foregoing movement, therounded surfaces 66 will initially pass over the inclined surface 92 andmove the cam members 73 and 75 apart against the forces of the springs96. When the rounded surface 66 passes beyond the apexes 94, the manualforce which is applied to button 46 to move the stem 38 outwardly of thebase 12, may be removed and the stem 38 will continue to moveautomatically to the full line cam pin 62 position as the force exertedby the springs 96 upon the cam members 73 and 75 urges the inclinedsurfaces against the rounded surfaces 66 so that the stem 38 will moveto its upper position and close the upper contacts of the switch 28.

The configuration and function of the cam members 76 and 78 as well asthe cam pin 64 are identical to the cam members 72 and 74 and the campin 62. Thus a detailed explanation of the operation of the cam members76 and 78 in response to the movements of the cam 64, in view of thepreceding description of the operation of the cam pin 62 in response tothe movement of the stem 38, is believed unnecessary.

If an illuminated version of the switch operator is desired, a lightmodule as disclosed in the Rothweiler et a1. patent is substituted forthe adapter 26 and the switches 28 are attached to a rear surface of thelight module. The light module includes suitable pins for transmittingmotion between the retainer 54 and the operating plungers 112 of theswitches and provides a support for a bulb 114 and suitable wireconnections to cause the bulb 114 to be illuminated when the switchoperator is in any one of the foregoing described positions in themanner disclosed in the Rothweiler et al. patent.

While certain preferred embodiments of the invention have beenspecifically disclosed, it is understood that the invention is notlimited thereto, as many variations will be readily apparent to thoseskilled in the art and the invention is to be given its broadestpossible interpretation.

What is claimed is:

1. A switch operator comprising: a base having a forward end and a rearend and a passage extending forwardly and rearwardly therethrough, apush button comprising a tubular stem portion axially movable in thepassage and a head portion disposed externally of the forward end of thebase, and means resiliently urging the stem portion toward at least oneaxial position in the passage, said means comprising a pair of membersmovable in a circumferential path about an outer peripheral surface ofthe tubular stem, a cam surface on each of said pair of members, meanscarried by the base for positioning said members adjacent the outersurface of the stem so that the cam surfaces on the pair of membersconfront each other, a cam pin immovably carried on an outer surfaceportion of the stern and positioned between the confronting cam surfacesof said pair of members, and means engaging the pair of members forconstantly urging the cam surfaces into engagement with the cam pin.

2. The structure as recited in claim 1 including an additional cam pinthat is carried on a portion of the outer surface of the stem so thefirst mentioned cam pin and the additional pins are on opposite sides ofthe stem and a second pair of cam members identical with the first pairof cam members have identical cam surfaces engaging opposite sides ofthe additional cam pin.

3. The structure as recited in claim 2 wherein the resilient meansincludes a pair of springs disposed on opposite sides of the stern and.each of said springs having ends engaging one of the cam members of thefirst and the second pairs of cam members.

4. The structure as recited in claim 1 wherein the stem portion and thehead portion are of translucent material.

5. The structure as recited in claim 1 wherein the cam surfaces have aV-shape and the cam pin is received within the apex of the V-shaped camsurface for resiliently maintaining the stem in a central positionwithin the passage and resiliently opposing movement of the stem fromthe central position.

6. The structure as recited in claim 1 wherein the cam surfaces have aV-shape with the apexes of the V-shaped cams of said confrontingsurfaces pointing toward each other whereby the stem is resilientlyurged from a central position in the passage toward either of twopositions on opposite sides of the central position.

7. The structure as recited in claim 1 including a member mounted on arear end of the stem to engage portions of the base to limit the forwardmovement of the stern in the passage and wherein portions of the headare engageable with portions of the base to limit rearwardly movement ofthe stem in the passage.

8. The structure as recited in claim 3 wherein the cam members of saidfirst and second cam members and the pair of springs are positionedwithin an annular groove provided by the base.

9. The structure as recited in claim 7 wherein the cam surfaces have aV-shape with the apexes of the V- shaped cams of said confrontingsurfaces pointing toward each other whereby the stem is resilientlymaintained in a position wherein the head engages the base or in aposition wherein the member mounted on the rear end of the stern engagesportions of the base.

References Cited H. O. JONES, Primary Examiner US. Cl. X.R.

